Cantabrians are spending thousands of dollars on "pet bonds" to ensure their four-legged friends can move house with them.

A lack of pet-friendly rentals has seen animal protection groups swamped with abandoned pets.

The Tenants Protection Agency (TPA) knows of one man who paid a $2000 pet bond to secure a rental, and "picky landlords" are being blamed for the increase in the number of abandoned pets.

Pam Howard, manager at Bromley's Dog Watch Adoption Centre, said the centre received "heaps of calls weekly" from people looking to rehome their dogs.

"There's a shortage of decent rental properties and so much demand. Landlords can be picky nowadays."

She said the main reasons for people giving up their dogs were because they were leaving New Zealand, their relationships were breaking up or they could not find a rental that allowed pets.

"Another problem is people who are having earthquake repairs done on their homes are struggling to find a short-term lease for two or three months, and if they can find one, then they can't find one that will let them take their pets," she said.

Independent Property Managers Association president Martin Evans said landlords would often state on a property listing that no pets were allowed but were "often partial to negotiation".

"If a tenant makes the effort to ring the owner, ask them to meet their pet, check out their references and that sort of thing, then an owner is more likely to agree to a pet."

A pet bond was a "good gesture", he said.

Property manager Tony Brazier said agents "need to lighten up a bit".

"Tenants should ask agents to contact the owner directly because it can make the difference."

He was "not too sure how legal pet bonds" were, and demand meant landlords felt it was "generally easier to say no instead of maybe or yes".

Abbey Draper, of New Brighton, who has been rehoming bull breed dogs for about eight years, said the rental shortage and "demanding landlords" were causing "innocent animals to be put down every day".

She has been looking after 10-year-old Mickey for about a month, but the dog needed to be rehomed. Mickey is deaf and has only three legs because she was hit by a bus when she was young.

Her owners were forced to give her away because their landlord said they could not have dogs.

She gets at least three phone calls a week from people needing their dogs rehomed.

TPA manager Helen Gatonyi said the rental shortage was "squeezing a longstanding issue", but there should be no need for a pet bond. "It just seems that landlords are keen to make a quick buck where possible," she said.

Alistair Helm, of properaz zi.co.nz, said a pet bond was a "very good idea" because it would encourage responsible ownership.